Can a notice of the 7th April 2017 termination the contract?

The first question necessary, it seems to me, to be determined is, did the notice of the 7th April terminate the contract? The agreement provided that, upon default by the purchaser, the defendants might declare the contract null and void by giving a 30 days’ notice in writing to that effect. By “a 30-days’ notice” I understand the parties to have meant a notice stating that, unless the purchaser’s default was remedied within 30 days of the delivery of the notice, or some date not earlier than that, the contract would become null and void. The notice given by the defendants was a notice declaring the contract null and void immediately. It was not the notice provided for in the agreement, and was in no sense a 30 days’ notice, and therefore, in my opinion, could not of itself have the effect of putting an end to the contract. If a proper notice had been given, it would have put an end to the contract, because the parties had so agreed; but, to entitle the defendants to determine the contract and retain for themselves the instalments paid, they must strictly comply with the requirements of the agreement. See Johnson v. Lyttle’s Iron Agency (1877), 5 Ch. D. 687, at 692; 46 L.J. Ch. 786, 36 L.T. 528. Not having done so, they are in the same position as if no such clause existed in the agreement.